Imagine you’re an animal species…okay, so you ARE an animal species.
So, imagine you’re a different animal species…a bird, for instance. It’s spring, you’ve arrived in your breeding territory, courted, mated, decided on the perfect nest site, and you’ve settled down to a month-long wait to incubate the two brown-speckled, olive-colored eggs you just laid. Okay, you’re a common loon…specifically a female common loon (because you just laid two eggs, remember?)
But you soon discover something’s far wrong! You’re inundated by the worst black fly hoard you’ve seen in years. They’re everywhere, crawling down your neck, in your nostrils, burrowing into your stinging eyes, your ears (do loons even have ears? Obviously, but with minimal exterior trim). The flies penetrate your tight feathers, bite your head, your back, crawl along your belly, and into all the orifices accessible from there…the uropygial gland near your tail, where you tap the oil to waterproof your feathers when you preen. Preen!
That sounds like a good idea. Time for a good preening! You slip the nest. Your mate is still on the neighboring lake for his afternoon feed. So he isn’t there to take his shift on the nest as usual. You just need a few minutes relief before getting back on the nest to face the hoards once again. The eggs should be okay till then.
They are, but when you return to the nest, the flies are even worse than before. Your mate returns and takes his place on the nest. You dive underwater, relieved by the cold, and stay under chasing a delicious perch for an extra long time, zigging here, zagging there…then snap! You have him, and eat al submerso (or whatever the term is for dining underwater). You stay submerged, exacting revenge on the biting hoards still clinging to your flesh, reveling in their discomfort (for a change).
When you finally surface, you find your mate on the water, furiously rubbing his head along his back, shaking his bill madly, diving in jerky fashion to dislodge the pests you so recently purged.
Over the next couple days, you and mate return again and again to the nest, taking shorter and shorter shifts, leaving the eggs for longer and longer periods until…well, at one point neither returns and the eggs sit abandoned. They sit, until long past the time that they’ll be viable, or some scavenger comes along and feasts on them.
If life seems unfair, be assured you’re not the only one. All across Minnesota, Wisconsin and Michigan’s U.P., loons just like you have been driven to the same fate. Many nests sit abandoned, eggs go wasted. Some loon pairs will re-nest, though, because most 2nd nests are only 1-egg clutches, chick production will suffer this year.
Simulium annulus is a black fly species that, around these parts, usually emerges during the earlier crane nesting period, whom they also bother to no end. In fact, establishing an eastern population of Whooping Cranes has had frustratingly limited success due somewhat to S. annulus. On occasions when spring weather arrives late, as in 2011, and before that, in 2008, annulus can just fall back on its alternate victim, the common loon.
Depending on the weather, S. annulus won’t be popular with crane researchers or loon lovers in any given year. But nature is what it is, and you can’t knock a species for playing the cards natural selection dealt it, whether a lowly black fly that times its emergence with the period when its victim is most vulnerable (on the nest), or the black bear who arrives on the river at the peak of the fall salmon run, just in time to build up fat reserves for the winter (and the birthing season).
So, we live with these setbacks, because they’re natural. But perhaps we can come to the loons’ aid. Some people who place artificial nesting islands (PVC rafts), are lining them with cedar chips. Crane researchers are recommending treating the marshes to suppress the hatch, a solution I’m uneasy with. S. annulus is an occurance of nature and a natural component of the food chain and the ecosystem. Birds have adapted to deal with it, and our meddling can too often have unintended, and foreseen, consequences.